Advancing evidence for safer opioid supply through population‑based research
When the unregulated drug supply in Canada became increasingly potent and unpredictable in the years leading up to and during the COVID‑19 pandemic, clinicians across the country faced an urgent question: how could they better protect people at the highest risk of overdose?
This context drove the rapid expansion of safer opioid supply (SOS) programs that prescribe pharmaceutical opioids as a safer alternative to the unpredictable illicit market. Although clinicians were seeing promising results on the ground, evidence was needed to understand how these programs were working, who they were reaching, and how outcomes compared to more established treatments such as methadone.
Dr. Tara Gomes, a senior scientist at ICES and principal investigator of the Ontario Drug Policy Research Network, recognized this evidence gap early. Working with ICES’ world‑class data infrastructure and analytic expertise, her team conducted the first‑ever quantitative evaluation of a safer opioid supply program, one located in London, Ontario. The paper became an important piece of evidence in North America examining how SOS programs function in real‑world settings and how they complement existing treatment pathways.
Safer supply is not meant to replace methadone. They are complementary tools, and for many people with complex needs, safer supply may be the entry point that keeps them alive long enough to engage more deeply in care.
Building the first population‑level evidence base
Following this early study which focused on patients accessing SOS from a single clinic in Ontario, Dr. Gomes’ team again leveraged ICES’ comprehensive health administrative datasets, allowing her to identify every person in Ontario who started safer opioid supply or methadone treatment between 2016 and 2021 — nearly 1,000 SOS recipients and more than 25,000 methadone recipients. This provided the first province‑wide comparison of who accesses these treatments and how their outcomes evolve over time, including overdoses, emergency department visits, hospitalizations, serious infections, and healthcare costs.
The findings showed what clinicians had long observed: people entering safer opioid supply programs tend to have more medically complex needs than those starting methadone. SOS recipients had higher rates of alcohol use disorder, HIV, hepatitis C, recent opioid toxicities, and prior hospitalizations for serious infections. Nearly 90% had already tried traditional opioid agonist treatment (OAT) within the past year.
“For over ten percent of safer supply clients, we were unable to find a matched methadone recipient in our study because their health needs were so complex,” Dr. Gomes explains. “That shows that safer supply is reaching people with high healthcare needs who might otherwise fall through the cracks.”
Among SOS recipients, the results were striking. For every 100 people:
- Emergency department visits dropped by approximately 9 visits per month;
- Hospital‑treated opioid toxicities decreased by 1 event per month; and
- Healthcare costs associated with emergency and hospital care fell by more than $90,000 per month.
Methadone recipients experienced similar improvements, reinforcing decades of evidence that methadone remains a cornerstone of treatment for opioid use disorder. However, the SOS findings were particularly meaningful given the high baseline risks observed in this population.
One of the most compelling findings was retention. People remained in safer opioid supply programs for a median of nine months, compared with 3.5 months for methadone — a 38% reduction in the likelihood of participants stopping treatment. In the context of opioid use disorder, treatment retention is critical, as risks of overdose and other harms increase substantially when people disengage from care. Higher retention suggests that SOS programs offer a model that resonates with and meets the needs of people who may not have been well‑served by traditional treatment approaches.
Comparing SOS and methadone in real‑world conditions
When comparing outcomes between the two programs, SOS recipients showed slightly higher risks of opioid toxicity, emergency visits, and hospitalizations. However, once researchers accounted for treatment discontinuation — examining all outcomes in the year after treatment initiation, regardless of whether someone remained in the program — most differences disappeared. The only exception was opioid toxicity, which remained somewhat higher among SOS recipients, likely reflecting their pre‑existing elevated risk and ongoing exposure to the illicit drug supply early in treatment.
These findings reinforce a key principle: safer opioid supply and methadone often differ in their clinical implementation. SOS is a harm‑reduction approach designed to reduce, not necessarily eliminate, exposure to the unregulated drug supply. Methadone programs, meanwhile, vary widely in their expectations around abstinence, which may reduce exposure to the unregulated drug supply more quickly for some individuals.
“Safer supply is not meant to replace methadone,” Dr. Gomes notes. “They are complementary tools, and for many people with complex needs, safer supply may be the entry point that keeps them alive long enough to engage more deeply in care.”
Part of the genesis of safer supply was clinicians’ desire to better support the needs of a very complex group of people for whom existing treatment options were not working
National influence and clinical impact
Nationally, Dr. Gomes’ research has played a key role in informing Health Canada, members of Parliament, and federal advisory committees. Her findings have contributed to federal investment decisions, and were cited in a court decision supporting continued access to safer supply programs in Alberta. Dr. Gomes was also invited as a panelist for the Joint OECD and U.S. Mission Policy Workshop on Addressing the Opioid Crisis in 2023 where she discussed the evidence for public health frameworks to the opioid crisis – including safer opioid supply programs – with governors from across the United States.
Beyond policy, the clinical impact of this work is significant. By providing clear evidence that both safer supply and methadone improve health outcomes — and that they serve distinct, complementary populations — this research helps clinicians adapt their approaches to meet patients’ needs more effectively.
“Part of the genesis of safer supply was clinicians’ desire to better support the needs of a very complex group of people for whom existing treatment options were not working,” says Dr. Gillian Kolla, an Assistant Professor in the Faculty of Medicine at Memorial University, and co-author of the study. “This study provides compelling evidence that safer supply programs were able to not only provide protection from overdose, but keep people engaged in care.”
Advancing evidence for a complex crisis
The opioid toxicity crisis continues to evolve, and no single intervention will solve it. But the evidence generated through ICES — led by Dr. Gomes and grounded in population‑level data — provides a clearer, more nuanced understanding of how different treatment models can save lives.
In a context where clinical decisions must adapt to shifting political, social, and drug‑market realities, this research provides clarity for healthcare providers. It also highlights both the strengths and limitations of safer opioid supply, underscores its role in serving people with complex health needs, and reinforces the importance of evidence‑informed policy and practice.
As Dr. Gomes reflects, “In the middle of a toxic drug crisis, we need every effective tool at our disposal — and safer opioid supply is proving to be a valuable one.”